18" x 28" or 28" x 18" Cube Core Eggcrate Return Air Grille 8" Round Duct Pipe + Product Details Size –

+ Product Details Size – 25"w X 32"h is the size for the duct opening measurement only

+ How To Measure A Grille

Actual Filter Size – 15 3/4"w x 7 3/4" x 1"

+ Product Details Perfect Fit & Easy Sizing - Designed for a 6" x 22" or 22" x 6" duct opening (measured at the opening)

18" x 28" or 28" x 18" Cube Core Eggcrate Return Air Grille 8" Round Duct Pipe + Product Details Size –+ Product Details Size 18" x 28" or 28" x 18" is the size for the duct opening measurement only, actual front end outer dimensions are approximately 19. 75" X 29. 75". High Quality High quality, rust free aluminum construction with smooth finished edges and counter sunk screw holes (screws included); no sharp edges.. Installation Location sidewall and ceiling. Design Cubic core eggcrate design Offers highest airflow efficiency at almost 95%, reducing